Significance of Scotch-tape anal swab technique in diagnosis of <i>Enterobius vermicularis</i> infection

, Cho, Seung Yull; , Kang, Shin Yong

doi:1975.13.2.102

Korean J Parasito > Volume 13(2):1975 > Article

Original Article


Korean J Parasitol. 1975 Dec;13(2):102-114. English. Published online Mar 20, 1994. http://dx.doi.org/10.3347/kjp.1975.13.2.102
Copyright © 1975 by The Korean Society for Parasitology


Significance of Scotch-tape anal swab technique in diagnosis of Enterobius vermicularis infection
Seung-Yull Cho and Shin-Yong Kang
Department of Parasitology and Institute of Endemic Diseases, College of Medicine, Seoul National University, Korea.


Abstract
The significance of Scotch-tape anal swab technique was evaluated in three communities of Korea, one in orphanage institute and two in rural populations, from November to December, 1975. Based on the epidemiological concept that the prevalence rate of Enterobius vermicularis infection in a community as "the proportion in the population who harboured E. vermicularis at certain point of time", the present authors treated the whole surveyed population with pyrantel pamoate disregard to the results of Scotch-tape anal swab and collected pinworms expelled in stool specimens during 2 consecutive days after the chemotherapy. Although the present authors could not collect the younger adult worms less than 3.54 mm in length after chemotherapy, the positive rates of pinworm collection in three surveyed communities were 80.6%, 92.5% and 91.4% respectively whereas the positive rates of single Scotch-tape anal swab were 52.4%, 53.6% and 57.1% respectively. These results denote that results of single anal swab do not represent the prevalence rate of Enterobius infection in a community. The results of successive two anal swabs and estimation of positivity in a population using Neyman's "Best asymptotically normal estimate" revealed 62.9% in the third trial group of this study and probability of finding eggs in single slide was 0.869. Comparing with the pinworm collection rate after the chemotherapy in this group the estimated positive rate was by far lower than that of pinworm collection(89.3%). The positive results of single anal swab did not correspond to the pinworm collection in average 9.1% of anal swab positive cases and the negative results did not correspond to pinworm collection in 81.3% of anal swab negative cases, when the data from three surveyed communities were amalgamated. These results must come from the principle of anal swab that detect the terminated parasitism. With rare exceptions, the anal swab negative cases harbour relatively fewer number of Enterobius than those of positive cases. And the mean number of E. vermicularis collected from anal swab negative cases was 9.1 whereas the number in anal swab positive cases was 31.5. By analyzing the data on the relationship between bathing interval and anal swab positive conversion, it was assumed that the positive rate of anal swab in a community represent the rate of appearance of gravid female Enterobius vermicularis through anus during approximately past two days prior to examination.

Figures


	Fig. 1 Distribution of cases with certain number of pinworms collected after chemotherapy with pyrantel pamoate in three surveyed communities. The blackened portion in bar means the cases with negative anal swab results.


	Fig. 2 Distribution of cases with certain number of pinworms collected after chemotherapy with pyrantel pamoate; amalgamation of data from three surveyed communities.

Tables


	Table 1 Age adjusted positive rate of Scotch-tape anal swab examination in two communities of this study


	Table 2 Successive pattern of E. vermicularis expulsion after chemotherapy in 20 children


	Table 3 Age adjusted pinworm collection rate and mean number of collected pinworms in three communities


	Table 4 Comparison of three parameters of examinations in E. vermicularis infection


	Table 5 Differences in pinworm collection rate and mean number of collected E. vermicularis in positive and negative groups of Scotch-tape anal swab examination in three surveyed communities


	Table 6 Interval between bathing and positive conversion of anal swab examination in 43 (52.4%) of 82 children


	Table 7 Interval between bathing and anal swab, and number of Enterobius eggs detected on single swab in orphanage institute


	Table 8 Results of two successive daily examinations of anal swab in 21 rural children of Kyongsang Nam Do with comparison with the results of pinworm collection after chemotherapy

References


1.	Akagi K. Nippon Ishikai 1953;30:5.

2.	Akagi K. Progress of Medical Parasitology in Japan 1973;5:229–279.

3.	Austin WC, et al. Nature 1966;212:1273–1274.

4.	Bumbalo TS, Fugazzotto DJ, Wyczalek JV. Treatment of enterobiasis with pyrantel pamoate. Am J Trop Med Hyg 1969;18(1):50–52.

5.	Choi DW, et al. Kyungpook Univ Med J 1973;14(2):423–429.

6.	Chyu I, et al. Theses of Catholic Med Coll 1963;7:239–244.

7.	Cram EB. Am J Dis Child 1943;65:46–59.

8.	Crofton HD. Parasitology 1971;62:179–193.

9.	Graham CF. Am J Trop Med 1941;21:159–161.

*10.*	Howes HL Jr, Lynch JE. Anthelmintic studies with pyrantel. I. Therapeutic and prophylactic efficacy against the enteral stages of various helminths in mice and dogs. J Parasitol 1967;53(5):1085–1091.

*11.*	Kagei N, et al. Jpn J Parasit 1971;20(3):228–234.

*12.*	Kawamoto S. Medicine & Biology 1956;40(3):94–97.

*13.*	LI SY, HSU HF. On the frequency distribution of parasitic helminths in their naturally infected hosts. J Parasitol 1951;37(1):32–41.

*14.*	Min HK, et al. New Med J 1974;17(4):51–57.

*15.*	Moriya S. Osaka J Med 1956;8:81–94.

*16.*	Park JY, et al. Kyungpook Univ Med J 1974;15(1):63–67.

*17.*	Rim HJ, Lim JK. Treatment of enterobiasis and ascariasis with Combantrin (pyrantel pamoate). Trans R Soc Trop Med Hyg 1972;66(1):170–175.

*18.*	Ryang YS. Korean J Public Health 1975;12(1):108–114.

*19.*	Sadun EH, et al. J Parasitol 1955;41 Suppl:41.

*20.*	Seo BS, Rim HJ, Loh IK, Lee SH, Cho SY, Park SC, Bae JW, Kim JH, Lee JS, Koo BY, Kim KS. [Study On The Status Of Helminthic Infections In Koreans]. Korean J Parasitol 1969;7(1):53–70.

*21.*	Yamamoto H, et al. Jpn J Parasit 1971;20(5):359–365.

*22.*	Yokogawa M, et al. Jpn J Parasit 1970;19(6):593–597.